The ACLU said Tuesday that it's representing one widow, 10 couples and one of the couples' two teenage daughters. The lawsuit, which was filed in federal court in Harrisburg, also asks a federal judge to prevent state officials from stopping gay couples from getting married in the state.

If the lawsuit is successful, Pennsylvania would become the 14th state to legalize gay marriage.

A 1996 Pennsylvania state law defines marriage as between a man and a woman, and says same-sex marriages, even if entered legally elsewhere, are void in Pennsylvania.

ACLU officials said that's unconstitutional because same-sex couples don't have access to the same legal and financial protections as do opposite-sex couples.